A long-running experiment finds a tiny particle is still acting weird

[ad_1] NEW YORK — Last outcomes from a long-running U.S.-based experiment introduced Tuesday present a tiny particle continues to behave unusually — however that’s nonetheless excellent news for the legal guidelines of physics as we all know them.

“This experiment is a big feat in precision,” mentioned Tova Holmes, an experimental physicist on the College of Tennessee, Knoxville who is just not a part of the collaboration.

The mysterious particles referred to as muons are thought of heavier cousins to electrons. They wobble like a high when inside a magnetic area, and scientists are learning that movement to see if it traces up with the foundational rulebook of physics referred to as the Normal Mannequin.

Experiments within the Sixties and Nineteen Seventies appeared to point all was properly. However checks at Brookhaven Nationwide Laboratory within the late Nineties and early 2000s produced one thing surprising: the muons weren’t behaving like they need to.

Many years later, a global collaboration of scientists determined to rerun the experiments with an excellent increased diploma of precision. The workforce raced muons round a magnetic, ring-shaped observe — the identical one utilized in Brookhaven’s experiment — and studied their signature wiggle on the Fermi Nationwide Accelerator Laboratory close to Chicago.

The primary two units of outcomes — unveiled in 2021 and 2023 — appeared to substantiate the muons’ bizarre conduct, prompting theoretical physicists to attempt to reconcile the brand new measurements with the Normal Mannequin.

Now, the group has accomplished the experiment and launched a measurement of the muon’s wobble that agrees with what they discovered earlier than, utilizing greater than double the quantity of information in comparison with 2023. They submitted their outcomes to the journal Bodily Assessment Letters.

That mentioned, it’s not but closing time for our most elementary understanding of what’s holding the universe collectively. Whereas the muons raced round their observe, different scientists discovered a technique to extra intently reconcile their conduct with the Normal Mannequin with the assistance of supercomputers.

There’s nonetheless extra work to be accomplished as researchers proceed to place their heads collectively and future experiments take a stab at measuring the muon wobble — together with one on the Japan Proton Accelerator Analysis Complicated that’s anticipated to begin close to the tip of the last decade. Scientists are also nonetheless analyzing the ultimate muon information to see if they will glean details about different mysterious entities like darkish matter.

“This measurement will stay a benchmark ... for a few years to come back,” mentioned Marco Incagli with the Nationwide Institute for Nuclear Physics in Italy.

By wrangling muons, scientists are striving to reply basic questions which have lengthy puzzled humanity, mentioned Peter Winter with Argonne Nationwide Laboratory.